Equine gastric ulcers present in the horse stomach, while hindgut ulcers present in the hindgut (specifically the colon). While many symptoms are similar – there are a few key differences to keep an eye out for
In addition, a basic understanding of equine anatomy is enormously beneficial in understanding the symptoms, causes and treatment for equine ulcers.
Horse ulcer symptoms: Gastric Ulcers and Hindgut Ulcer Symptoms
Horse ulcer symptoms are often the same, whether it’s gastric or hindgut. Here are the general signs of an ulcery horse:
- weight loss and low body condition
- irritability and ‘nappiness’ while being ridden
- a cranky attitude
- behavior indicating discomfort, such as pawing or laying down
- loss of appetite
Hindgut specific horse ulcer symptoms
The location and size of the horse’s hindgut means that the below symptoms are indicitative of potential hindgut ulcers
- sensitivity in the flank area
- difficulty bending, collecting, and extending
- soft or loose droppings
- repetitive behaviours like weaving or cribbing
- sudden dislike of grooming & rugging
For a proper diagnosis a gastroscope can identify gastric ulcers in horses. However, gastroscopes are not effective at diagnosing hindgut ulcers. For a non invasive method of checking for ulcer symptoms at home, follow this tutorial.
Anatomy of the digestive system
To greater understand the causes, symptoms and treatment of equine ulcers, understanding the digestive anatomy is paramount.
In basic terms, the front part of the digestive system or the ‘foregut’ consists of the mouth, esophagus, stomach and small intestine. The back part of the digestive system is called the ‘hindgut’ and consists of the caecum, large colon, small colon, rectum and anus.
Both the stomach and the colon are susceptible to ulcers.
The stomach has 10% of the capacity of the small intestine. This means that horses cannot handle large portions of feed at once. They are much better suited to small amounts fed consumed regularly.
Furthermore, the stomach is divided into an upper and lower section. These sections have different types of stomach lining.
- The upper section is known as the squamous mucosa. This has a thinner stomach lining and no glands.
- The lower section is called the glandular mucosa. This section has much more robust lining and contains glands that produce stomach acid.
Most ulcers form in the upper section of the horse’s stomach (the sqamous) as it has poor protection against stomach acid. Ulcers are less common in the glandular mucosa as it has better defences for acid protection.
The hindgut is about 7 metres (23 feet) in length with a volume of 140-150 litres (37- 40 gallons) .
Horses are known as ‘hindgut fermenters’ as they utilise good bacteria to ferment forage in their colon, creating volatile fatty acids which produce most of the body’s energy.
Ulcers occur in the hindgut as the result of erosion to the mucosa in the caecum and/or colon.
Gastric Ulcers vs. Hindgut Horse Ulcers
Equine gastric ulcer syndrome ‘EGUS’ is a broad term used to describe any ulceration to the horse’s stomach lining. This can then be further categorised:
- Equine Squamous Gastric Ulcer Syndrome (ESGUS); are ulcers affecting the squamous mucosal lining.
- Equine glandular gastric ulcer syndrome (EGGUS) for ulcers affecting the glandular mucosal lining.
Squamous vs. Glandular Mucosa of the Stomach
Squamous ulcers – ESGUS
Squamous ulcers will only occur in the upper third of the stomach and indicate increased acid exposure to this area. Ulcers will form quickly and normally occur as a result of low forage or high grain diets, gastric splashing & stressors like transportation.
Glandular ulcers – EGGUS
Glandular gastric ulcers will only occur in the lower section of the stomach. These ulcers form slowly and indicate that the mucus coat that protects the glandular tissue has failed. The reason the mucus coat fails is not well understood but could be attributed to many factors including medication, coarse food (alfala hay) or bacteria.
Like gastric ulcers, hindgut ulcers occur as a result of damage to the hindgut lining. There are two common causes behind this.
Right dorsal colitis
This often occurs as a result of Non-steroidal anti-inflammatory drug (NSAID) exposure. Phenylbutazone or ‘bute’ is the most commonly used equine NSAID. These medications stop the production of prostaglandins in order to stop pain and inflammation. However, this also affects the mucus production and blood flow that keeps the hindgut lining healthy and protected.
This is simply a raised level of acidity in the hindgut. High grain diets can be too much for the equine stomach to digest. Excess undigested grain moves on to the hindgut which causes lactic acid production. This increased acidity level is thought to reduce mucus production and leave hindgut lining unprotected from further acid exposure. Parasite burden is also known to cause problem to the hindgut.
Treatment and prevention
Omeprazole is the go-to medication for equine squamous gastric ulceration syndrome. It controls gastric acid production which prevents ulcers from forming. In addition, Omeprazole will alleviate pain. Generally speaking, omeprazole will heal ulcers within 28 days.
Treating EGGUS with omeprazole alone is much less effective.
Instead it is recommended that you treat with both omeprazole and a mucosal protectant like sucralfate. Sucralfate forms a gel when reacting with stomach acid and this forms a protective film over ulcerated or inflamed areas. This allows the existing ulcers to heal, while the omeprazole stops new ulcers from forming.
Hindgut Ulcer Treatment:
A key place to start treatment is by discontinuing or reducing the use of NSAIDs.
Sucralfate is recommended to bind to and protect ulcers from further acid exposure. It is also suspected that once sucralfate binds to an ulcer it may stimulate further protective chemical production in the area.
Why give sucralfate in conjunction with something else?
Sucralfate doesn’t actually treat ulcers. It simply creates a protective barrier that protects existing ulcers from acid exposure and allows them time to heal as well as protects vulnerable mucous lining. For example, when treating EGGUS, sucralfate is often given in conjunction with omeprazole to control secretion of acid and allows ulcers time to heal.
When do I give sucralfate?
It is recommended that sucralfate be given on an empty stomach – at least 1-2 hours before a meal – as this coats the stomach most effectively. Ideally given 3 times per day as it is effective for only 8hours.
Symptoms can improve before an ulcer is fully healed so it is recommended to follow the dosage instructions . It is also suggested that other medications & supplements not be taken within 2 hours before or after sucralfate. Talk to your vet about how it may interact with other medications you are giving your horse.
Why doesn’t omeprazole help hindgut ulcers?
It is suspected that omeprazole can make hindgut ulcers worse. As it suppresses stomach acid it can allow undigested food to pass through the stomach into the hindgut. This can cause lactic acid production and worsen hindgut ulcers.
Horse ulcer symptoms can be similar for both types of ulcers in horses. Learn more about horse ulcer symptoms here – Equine Gastric ulcer Syndrome.